Apparatus for making conduit



July 2, 1963 H. PENDORF APPARATUS FOR MAKING CONDUIT Original Filed NOV.2, 1956 4 Sheets-Sheet 1 INVENTOR.

HAROLD PENDORF 83M MJ h ATTO July 2, 1963 H. PENDORF 3,095,612

APPARATUS FOR MAKING CONDUIT Original Filed Nov. 2, 1956 4 Sheets-'Sheet2 IN V EN TOR.

HAROLD PENDORF 4 BKM Mfm ATTOR YS July 2, 1963 H. PENDORF 3,095,612

APPARATUS FOR MAKING CONDUIT v Original Filed Nov. 2, 1956 4Sheets-Sheet 5 e INVENTOR.

HAROLD PENDORF ATTO July 2, 1963 H. PENDORF APPARATUS FOR MAKING CONDUITOriginal Filed Nov. 2, 1956 4 Sheets-Sheet 4 "A H loIl 27'/ 'l LINVENTGR.

HAROLD PENDORF BMMQ/ ATTO EYS United States 'Ilhis invention relates toapparatus for the treatment of a porous-walled liexible conduit, suchIas la crush-proof ilexible metal radio-shielding conduit andthe like.More particularly, the invention relates to appanatus nor impregnatingthe walls of such conduit with flexible nonporons materials.

- 'Ihis application is a division of .application 'Serial No. 620,023,.tiled November 2, 1956, now Patent No. 2,981,- 982, issued May 2, 1961.

One of the objects of the present invention is to provide `a novelappanatus for impregnating porous-walled tubes.

Another object ofthe invention is to provide an improved apparatus forimpnegnating tub-es of the indicated character such tubes having one ormore layers therein which initially are prone to displacementlongitudinally of the conduit.

A `further object is to provide an improved apparatus for impregnatingporous-walled tubes having one or more layers composed of one or moreinitially :axially displaceablc members by introducing impnegnatingcornpound to the tube in such nia-nner as not substantially to disturb'the initial spacing of the displaceable mem bers.

Yet another object of the invention is to provide an impnoved apparatusfor making an impregnated flexible conduit, one inner layer of which isformed by 'a helicaltly wound wire, the turns of which are spacedsubstantially uniiorrnly along the length of fthe conduit.

A still `further object is to provide Ian improved sirnpliiied mold inwhich the conduit is positioned duri-ng "am o f the describedimpregnating operation, said mold includpose of illustration only, andare not intended as a definition of the limits of ,the invention.

In the drawings, wherein like reference characters refer to like partsthroughout the sevenal views,

FIG. 1 is a view in elevation of la typical flexible conduit which maybe treated in accordance with the invention, :a central portion ot theconduit being broken away, the tubes making up the portion of theconduit wall shown at the Ileft being progressively peeled or cut away;

FIG. 2 is a lfragmentary view in elevation, generally corresponding tothe left hand portion of PIG. 1, of the conduit ,after an impregnatingtreatment in accordance with the invention; v

FIG. .3 is an enlarged fragmentary view in radial section through theconduit of FIG. 2, the section being take-n along the iine 3 3 of FIG.2;

FIG. 4 is a View in plan of the upper and lower parts of an embodimentot mold, useful .in carrying out the method of the invention, the uppermold part having 3,095,612 Patented July 2, 1963 ICC 2 been lidted fromthe :lower mold part and turned upside down;

lFIG. 5 a View in vertical longitudinal axial section through the moldor" FIG. 4 with the conduit being treated shown as positioned therein;

FIG. 6 is a fragmentary View in vertical section Ithrough the mold and aconduit positioned therein, the section being .taken generally Ialongthe line 6-6 of FIG. 5; and

FIG. 7 is' a view in elevation ot the assembled mold, having a conduitto be treated contained therein, ya portion of a compound-supplyinginjection device being shown cooperating with the mold.

The embodiment of the conduit illustrated in the 'accompanying drawings,by 'way of example, is in the form of a composite flexible metal walledtube which is useful, vfor example, as a shield for conductors in theignition system of an internal combustion engine. When the metal wall ofthe conduit is properly grounded, it forms -an eiective shield againstthe radiation of electro magnetic vibrations, set up `by ftheignition-system, which would otherwise interfere with nadiecommunication. The conduit shown is of the type which strongly resistscnushing forces, thereby insuring that the conductor contained within itwill not be injured in spite of rough handling ot the conduit. When theconduit is employed with an airplane engine it is, .of course, alsosubjected to extremely adverse conditions' including vibration 'by windIcurrent and engine operation, exposure to extremes of high and louItemperatures, electrical corona, grease, oil, ,and moisture, as well aswide variations in altitude.

The novel conduit construction resulting from use of the apparatus ofthe invention will be more readily understood by a comparison of FIG. 1,wherein the assembled but unimpregnated conduit is designated 10, andFIG. 2, wherein the impregnated portion of the conduit shown isdesignated 21. As indicated in FIG. 1, the conduit comprises a pluralityof superposed telescoped tubes or sleeves made of braided wire, threebeing shown in the illustrative embodiment. The innermost of such tubesis designated 14, the intermediate Wire tube being designated`16, andthe outermost wire tube being designated 18. The Wire strands formingsuch tubes may be braided in a normal manner to make up the tubes, andmay be constituted in various forms known to the art. In a preferredembodiment, each strand is made up of about eight small wires laid sideby side to simulate a at strip. The

tubes may be braided separately and inserted into one another, or thelarger diametered tubes may be braided directly on the smaller ones as acore. The smallest or inner tube is generally braided on a solidremovable core, which, of course, has been removed from the illustratedconduit. Telescoped within braided tube 14 is a helcally wound wirehaving closely spaced turns so that it, in etect, forms a fourth,innermost porous tube 12. The wire forming tube 12 is preferably made ofa relatively stiff metal, such as stainless steel, so as to make thecomposite conduit wall markedly resistant to crushing forces.

The end portions of wire tubes 12, 14, 16 and'18 are rmly securedtogether by means of solder indicated at 20, and each said end issecured by means, such as solder also designated 20, within the sleeveof a ilanged terminal fitting such as that shown at 11 at the left and11' at the right in FIG. l.

For the purpose of rendering the conduit moistureproof, and at the sametime to provi-de a smooth, nonchaiing inner surface on the conduit toprotect insulated wir-e passing therethrough against damage, theassembled conduit member 10, made up of superposed tubes 12, 14, 16 and18, and, in the embodiment shown having terminal fittings 11, 11connected thereto, is treated in a novel manner now to be described toprovide therein a lining 13 and at the same time to provide thin layers28, 15 and 17, of the lining material, respectively, between adjacentlayers of the metal tubes making up the wall of the conduit. A thincoating 19 of such cornpound is preferably also :disposed upon the outersurface of metal tube 18.

The layers 2S, 15, 17 and 19 are integrally connected to each other andto lining 13 through the porous braiding of the intervening braidedmetal tubes and through the interstices between successive turns of wiretube 12, respectively. Besides forming a non-chating lining on theconduit, the impregnating material also, in effect, locks the turns ofwire of tube 12 against displacement longitudinally of the conduit.

In addition to its non-chafing properties, the material of which lining.13 and layers 23, 15, 17 and 19 is made should have good resistance tocorona and should not contain volatiles for some uses. The liningmaterial should be non-porous, flexible and resilient. When set, saidmaterial should retain these properties when subjected to a wide rangeof temperatures and exposed to grease, gasoline aud moisture. A suitablematerial should also be tough and have the ability to conform to thebraided metal tubing and withstand continual bending stresses.Elastomers, such as those having a polyvinylchloride base and siliconerubbers have been found suitable. One suchsilicone rubber or silasticcompound is that sold under the trade name Dow Silastic 132.

Another lining material which has been found suitable for use inflexible conduits for radio shielding aircraft engine ignition systems,for example, is a synthetic plastic material known in the trade as aplastisoL i.e., a fluid dispersion of polyvinylchloride polymer in aplasticizer which may be converted by heat alone to an elastomeric vinylcompound. This material has a polyvinylchloride base with suitableplasticizers and a heat stabilizer. Suitable lillers may be used, ifnecessary, to vary the ilow characteristics. A suitable compositionconsists of ten parts by -wei-ght `of polyvinylchloride, such as Geon#121, lfour parts of Rohm and Haas Paraplex C-SO, two parts of ParaplexC-60 (a polyester) and two parts of a heat stabilizer consisting of amixture of Paraplex C-SO and dibasic lead phthalate in equal parts. Thismaterial is prepared 4for application at normal room temperature. TheGeon #121 should be in the form of a ine powder, the plasticizers(Paraplex) are a-dded in liquid form, and the heat stabilizing mixtureis added in finely powdered, well-mixed form. The ingredients are thenmixed thoroughly, preferably under vacuum.

The impregnating compound such as silicone rubber or plastisol isapplied to the above-described structure 10 (FIG. l) in accordance withthe novel method of the invention, one embodiment of which will now bedescribed. Such method is conveniently carried out by use of the moldshown in FIGS. 4, 5, 6 and 7.

Such mold, which is generally designated 24, is of the longitudinallydivided type having a lower half 25 and an upper half 26 which whenassembled have an interface disposed longitudinally of the mold andalong planes diametral of the two confronting semi-cylindrical moldcavity portions 27 and 29 in the respective mold halves. Such two moldcavity portions Iform a cylindrical mold cavity 23 having a diameterslightly greater than that of the outer braided tube 18 of conduit 1t).Conduit 10 is disposed in the mold cavity in extended condition, beingheld in that condition and sealed at its ends to the mold cavity lbymeans to be described and generally designated 30 at the left (FIG. 7)and 31 at the right.

When the mold has been assembled as shown in FIG. 7, with conduit r10therewithin, it is then impregnated by a compound 22, such as thosedescribed above, supplied by an injection cylinder shown generally at32. Cylinder 32 has a piston 34 which is thr-ust downwardly bymechanism, not shown, to deliver plastic material 22 outwardly ofcylinder 32 through nozzle 35. The outer end of the nozzle is tapered,and is received in a similarly tapered opening 36 which is centrallylocated in the upper portion 26 of the mold above the conduitreceivingcavity portion 29 therein. The thus delivered plastic material 22 isforced inwardly to a central throat 38 and thence into a longitudinallydisposed distributing channel 37 which lies centrally above and parallelto the mold cavity 23. A plurality of equally spaced vertical passages39 connect the bottom of channel 37 with the top of the upper portion ofthe mold cavity, so that the plastic material 22 is delivered to theconduit within the mold cavity substantially simultaneously and at thesame rate in Zones spaced along a longitudinal extending area at yoneside of the conduit and thus tends to flow symmetrically down along thesides of the conduit and inwardly through the porous sidewall of theconduit.

The construction of the means whereby the ends of the conduit 10,including terminal fittings 11 and 11', are positioned in the moldcavity and sealed to the walls thereof -will be more readily apparent onconsideration of FIGS. 4 and 5. As there shown, the lower mold part 25has an enlarged semi-cylindrical passage 42 at the left therein coaxialof mold cavity 27, and a similar enlarged semi-cylindrical passage 45 atthe right end of such mold part. Upper mold part 26 is somewhat shorterthan mold part 25, and is received between vertical end flanges 40 and41 on the lower mold part. Mold part 26 has similar enlargedsemi-cylindrical passages 44 and 45 confronting passages 42 and 45,respectively, in mold part 25. The enlarged cylindrical passages thusprovided at the ends of the conduit-receiving mold cavity 23 havediameters such that they freely receive the nuts 51 and 54 disposed onsleeve members 11 and 11', respectively, of the tw o terminal members ofthe conduit (FIG. l). A cylindrical block 47 is slidably mounted in theleft enlarged passage in the mold, and a cylindrical block 49 isslidably mounted in the right enlarged passage in the mold. The slidableblocks 47 and 49 provide means whereby the conduit is suitablypositioned within the mold cavity 23 and the terminal fittings on theconduit are sealed to the ends of the mold cavity. The conduit holdingmeans includes an externally threaded hollow |boss or nipple 50-disposed on the inner face of block 47 coaxial with theconduit-receiving cavity 23, and a similar hollow boss or nipple 52disposed on the inner face of block 49. The outer ends of theconduitreceiving cavity 23 are provided with shallow counterbores whichsnugly receive, respectively, sleeve portions 11 and 11' of the twoterminal fittings on the conduit. Mold part 25 is provided with left andright shallow countenbore portions 55 and 57, and mold part 26 isprovided with shallow counterbore portions 56 and 59, such counterboreportions cooperating to form the aforesaid counterbores receiving thesleeve portions of the terminal ttings on the conduit.

The thus formed counterbores have transverse shoulders at their innerends adapted to be engaged by the inner ends of the sleeves of theterminal fittings when the parts are disposed as shown in FIG. 5.

It is desirable that only so much of compound 22 be injected into themold as is necessary to form the layers 13, 28, 15, 17 and 19 and toimpregnate and ll the voids in the porous metal tubes forming theconduit wall. This avoids the necessity of draining excess compound romthe central passage in the treated conduit. It is also 4desirable thatthe inner surface of lining layer 13 `of the compound be substantiallyuniform in the thickness. Thus, in the embodiment of the mold shown,there is provided a mandrel 60 which is disposed within the conduit 10in the mold coaxially of the wall of mold cavity 23.

The mandrel and the means for mounting it are shown most clearly inFIGS. 5 and 6. As shown, mandrel 60 has a circular cylindrical portion61, at the left in FIG. 5, and a portion 62 of truste-conical shapehaving the surface at its left hand, larger end merging smoothly withthat at the right of portion 61. The left hand end of the mandrel isrotatably supported coaxial of mold cavity 23 in a journal 64 in block47, the right hand, free end or nose of the mandrel being supported in acentral guiding bore l65 in block 49. The mandrel projects through'block 47, and is provided outwardly of the block with a knob `66whereby it may be rotated about its axis to rfree it from lining layer`13 tof the impregnating compound after the conduit has beenimpregnated.

A jack screw 67 is threaded into an opening in vertical ilange member40, screw 67 lying coaxial of the mandrel. A similar jack screw 70 isthreaded into an opening in vertical lflange 41 and is also locatedcoaxial of the mandrel. The screws 67 and 70 may be rotated by knobs y69and 71, respectively, to advance the inner ends of the screws to contactknob I66 and block 49, respectively, whereby to advance blocks 47 and 49toward the ends of the mold cavity 23 or to retract the screws to allowthe blocks to be moved away from each other.

The conduit is impregnated as follows. It will be assumed that theconduit has been assembled as shown in FIG. l, and that the partsthereof are clean and dry. The upper mold part 26 is removed from lowermold part 25, jack screws 67 and 70 are retracted somewhat, the block 47with mandrel 60 mounted thereon, together with block 49 are lifted as aunit from bottom mold part 25, and block 47 is then moved away fromblock 49 to free the nose of the mandrel.

An untreated conduit 10 is then telescoped over the mandrel, and nut 51of litting 11 is screwed home on threaded nipple 50. The free end ofmandrel 60 is thereafter inserted into bore y65 in block 49, and nut 54is then screwed home on threaded nipple 512. The blocks 47 and `49,mandrel 60, and conduit 10, now assembled as a unit, are lowered intoplace in the cavity in lower mold half 25 so that the conduit lies inmold cavity portion 27, the sleeve portions of the terminal iittings liein the respective countenbores at the ends of the mold cavity, and theassembled nuts 51 and 54 and blocks 47 and 49 lie within enlarged cavityportions 42 and 45 of the lower mold half. rIlhe upper mold half 26 isthen assembled upon the lower mold half, and

jack screws 67 and 70 are advanced to thrust the end' surfaces of nuts51 and 54 toward the respective inner confronting 4end 'of enlargedcavities 42 and 4S. The snug reception of the sleeve portions of theterminal fittings 11 and 11' in the shallow countenbores at the ends ofthe mold cavity, the tight end engagement between the inner ends ofsleeves 11 and 11 and the transverse shoulder at the inner ends of thecountenbrores receiving such sleeves, and/or the tight engagementbetween the end surfaces of the nuts 51 and `54 with the ends of theenlarged cavities substantially seal the ends of the conduit to thewalls of the mol-d cavity.

Impregnating material 22 may now be introduced into the mold bypresenting injection cylinder 32 thereto, as indicated in FIG. 7, andthen thrusting piston 34 thereof downwardly until material 22 has iilledthe interstices or voids in the porous side walls of the conduit and hasformed the layers 13, 28, 15, 17 and 19 of such impregnating compound.IBecause the compound is introduced to the outer wall of the conduitover an area disposed longitudinally of the conduit, and atsubstantially uniformly spaced zones in said area, pressure conditions,both of the impregnating compound and of the air which is displaced fromthe mold cavity and conduit wall in advance of the inflowing compound,are substantially symmetrical both longitudinally and laterally of themold cavity. As a result there is little, if any, tendency for theinflowing compound to disturb the initial longitudinal spacing of theturns of wire making up inner tnbe 12.

After the conduit has been fully impregnated, the thrusting force isremoved from piston 34, cylinder 32 is removed from cooperation with themold, jack screws 67 and 70 are lbacked olf, and the mold is opened. Thediameter of vertical passages 39 in mold half 26 is preferably suchthat, taken with the viscosity of compound 22, tiow of compound 22ceases when pist-on 34 ceases to be thrust downwardly.

The assembly of blocks 47 and 49, the mandrel 60', yand impregnatedconduit 21 is then removed from mold half Z5. Preferably the assembly isnow given a pre-bake treatment with the mandrel in place within theconduit, to insure that the lining shall be of uniform thickness andshall have a smooth inner surface. Such pre-bake is conducted at Iapredetermined temperature and for a predetermined time, depending uponthe character of the plastic material employed, to give such material apreliminary set. After the pre-bake, nut 51 is unscrewed from nipple 50,and blocks 47 and 49 are pulled away from each other, therebywithdrawing the mandrel from the conduit. Preferably the mandrel 60` isturned by knob 66 during this operation. Nut 54 may then be unscrewedfrom nipple 52 on block 49. The mold is then ready for treatment ofanother conduit 10.

The thus pre-baked conduit 21 is then transferred to a suitable `ovenand baked for a time and at a temperature, both suitable for the plasticmaterial employed, to complete the setting and curing of theimpregnating compound. The baked conduit is then removed from the ovenand allowed to cool to room temperature, `after which it is cleaned toremove excess impregnating compound therefrom as required.

Use of the apparatus of the present invention provides an improvedmositure-proof radio shielding conduit of the type which has one or morelayers of initially longitudinally displacea-ble components, such as theturns of a helically wound reinforcing wire locked in place in itssidewall structure, an improved simplified, reliable and effectivemethod for fabricating such conduit, and a novel apparatus by which themethod may be carried out. The novel apparatus makes it possible to makesuch conduits with assurance as to the uniformity and high quality ofthe finished product and to effect such fabrication rapidly and at lowcost with a minimum waste of materials. The apparatus of the inventionis simple, rugged, and easily operated. Such apparatus producesimpregnated conduits which -are substantially uniform throughout theirextents, and also from conduit to conduit. The helically wound,initially axially displaceable component in the conduit sidewall is notsubstantially displaced, and the inner coating or lining 13 is generallysmooth and of substantially uniform thickness.

Although only a single embodiment of the apparatus of the invention hasbeen illustrated in the accompanying drawings and described in theforegoing specification, it is lto be expressly understood that theinvention is not limited thereto. For example, the apparatus may beshaped to treat conduits having a variety of shapes, the contour of themold cavity and the shape of the mandrel being altered as required bythe shape of the conduit to be treated. Various other changes -may alsobe made, such as the specific materials, temperatures and the likesuggested herein by way of example and in the design and arrangement ofthe parts illustrated without departing from the spirit and scope of theinvention as the same will now be understood by those skilled in theart.

What is claimed is:

l. Apparatus adapted for lining and impregnating with a sluggish fluidcompound the porous walls of a conduit having sleeve-like terminaliittings with flanges adjacent their outer ends, comprising alongitudinally divided mold having an elongated cavity formed betweenconfronting parts of the mold, said cavity in its generally central partbeing in rthe form of a mold cavity receiving the conduit in extendedcondition, at portions thereof immediately 7 outwardly of the moldcavity being in the form of counterbores of larger diameter than themold cavity and of such diameter as snugly to receive the adjacent endpor-tions of the sleeve-like terminal fittings on the conduit, and atits outer ends being in the form of passages of larger diameter than thecounterbores and receiving the flanges of the terminal fittings on theconduit, the junctions between the mold cavity and the counterbores andthe junctions between -the counterbores and the passages being in theform of generally transverse annular shoulders, the sleeves on theterminal fittings lying within the counterbores and having generallytransverse inner end surfaces overlying the shoulders at the oppositeends of the mold cavity, a block beyond each end of the mold cavity,each block being supported in and guided by the respective passage formovement toward and away from the respective end of the mold cavity andfor easy removal from the passage, means for detachably securing eachrespective terminal iitting and its block together in the form of anassembly, each assembly having a generally transverse annular shoulder,each said last named annular shoulder closely confronting the junctionbetween the counterbore and the respective passage in the mold, eachblock having an inwardly facing abutment surface thereon engaging theouter face of the respective terminal fitting when the block and fittingare in assembled relationship, means mounted on the mold for thrustingeach of the assemblies toward the mold cavity so as forcibly to thrustat least one of the inner end surfaces of the sleeve and the last namedannular shoulder of the assembly into sealing engagement with the innerend of the respective counterbore and the junction between therespective counterbore and the passage, respectively, and means in themold for introducing the compound under pressure to the outer surface ofthe conduit over an area disposed generally longitudinally of theconduit, whereby the conduit and blocks may be inserted and removed fromsaid cavity as a conduit-block assembly when the mold sections areseparated.

2. Apparatus as defined in claim 1, comprising a mandrel extendingthrough and having a close moving fit Within one of said blocks andadapted to be received within and to extend through the conduit and theterminal fittings thereon, a recess in the other of said blocks forjournalling the other end of the mandrel which protrudes beyond therespective terminal fitting, and means on the mandrel for rotating themandrel, whereby the mandrel forms part of said removable conduit-blockassembly.

3. Apparatus as dened in claim 1 wherein the conduit has axiallyoutwardly facing nuts on the terminal fittings inwardly of the iiangeson such fittings, said passages in the mold receive the nuts on therespective terminal littings, and said blocks have threaded bossesaligned with the ends of the mold cavity and threadedly receiving thenuts on the respective terminal fittings, comprising upstandingplate-like members attached to the ends of one of the mold parts and atleast partially overlapping the other of the mold parts when the moldparts are together in confronting operative position, and wherein themeans for thrusting the blocks toward the mold cavity comprise screwsthreaded into the plate-like means, extending aX- ially of the moldcavity, and abutting the outer ends of the respective assemblies.

References Cited in the file of this patent UNITED STATES PATENTS1,366,342 Atwood Ian. 25, 1921 1,964,202 Hooper June 26, 1934 2,364,911Osella Dec. 12, 1944 2,501,863 Cox Mar. 28, 1950 2,759,864 Kuebler Aug.21, 1956 FOREIGN PATENTS 374,842 Great Britain June 2, 1932

1. APPARATUS ADAPTED FOR LINING AND IMPREGNATING WITH A SLUGGISH FLUIDCOMPOUND THE POROUS WLLS OF A CONDUIT HAVING SLEEVE-LIKE TERMINALFITTINGS WITH FLANGES ADJACENT THEIR OUTER ENDS, COMPRISING ALONGITUDINALLY DIVIDED MOLD HAVING AN ELONGATED CAVITY FORMED BETWEENCONFRONTING PARTS OF THE MOLD, SAID CAVITY IN ITS GENERALLY CENTRAL PARTBEING IN THE FORM OF A MOLD CAVITY RECEIVING THE CONDUIT IN EXTENDEDCONDITION, AT PORTIONS THEREOF IMMEDIATELY OUTWARDLY OF THE MOLD CAVITYBEING IN THE FORM OF COUNTERBORES OF LARGER DIAMETER THAN THE MOLDCAVITY AND OF SUCH DIAMETER AS SNUGLY TO RECEIVE THE ADJACENT ENDPORTIONS OF THE SLEEVE-LIKE TERMINAL FITTINGS ON THE CONDUIT, AND AT ITSOUTER ENDS BEING IN THE FORM OF PASAGES OF LARGER DIAMETER THAN THECOUNTERBORES AND RECEIVING THE FLANGES OF THE TERMINAL FITTINGS ON THECONDUIT, THE JUNCTIONS BETWEEN THE MOLD CAVITY AND THE COUNTERBORES ANDTHE JUNCTIONS BETWEEN THE COUNTERBORES AND THE PASSAGES BEING IN THEFORM OF GENERALLY TRANSVERSE ANNULAR SHOULDERS, THE SLEEVES ON THETERMINAL FITTINGS LYING WITHIN THE COUNTERBORES AND HAVING SHOULDERS ATTHE OPPOSITE ENDS OF THE MOLD CAVITY, A THE SHOULDERS AT THE OPPOSITEENDS OF THE MOLD CAVITY, A BLOCK BEYOND EACH END OF THE MOLD CAVITY,EACH BLOCK BEING SUPPORTED IN AND GUIDED BY THE RESPECTIVE PASSAGE FORMOVEMENT TOWARD AND AWAY FROM THE RESPECTIVE END OF THE MOLD CAVITY ANDFOR EASY REMOVAL FROM THE PASSAGE, MEANS FOR DETACHABLY SECURING EACHRESPECTIVE TERMINAL FITTING AND ITS BLOCK TOGETHER IN THE FORM OF ANASSEMBLY, EACH ASSEMBLY HAVING A GENERALLY TRANSVERSE ANNULAR SHOULDER,EACH SAID LAST NAMED ANNULAR SHOULDER CLOSELY CONFRONTING THE JUNCTIONBETWEEN THE COUNTERBORE AND THE RESPECTIVE PASSAGE IN THE MOLD, EACHBLOCK HAVING AN INWARDLY FACING ABUTMENT SURFACE THEREON ENGAGING THEOUTER FACE OF THE RESPECTIVE TERMINAL FITTING WHEN THE BLOCK AND FITTINGARE IN ASSEMBLED RLATIONSHIP, MEANS MOUNTED ON THE MOLD FOR THRUSTINGEACH OF THE ASSEMBLIES TOWARD THE MOLD CAVITY SO AS FORCIBLY TO THRUSTAT LEAST ONE OF THE INNER END SURFACES OF THE SLEEVE AND THE LAST NAMEDANNULAR SHOULDER OF THE ASSEMBLY INTO SEALING ENGAGEMENT WITH THE INNEREND OF THE RESPECTIVE COUNTERBORE AND THE JUNCTION BETWEEN THERESPECTIVE COUNTERBORE AND THE PASSAGE, RESPECTIVELY, AND MEANS IN THEMOLD FOR INTRODUCING THE COMPOUND UNDER PRESSURE TO THE OUTER SURFACE OFTHE CONDUIT OVER AN AREA DISPOSED GENERALLY LONGITUDINALLY OF THECONDUIT, WHEREBY THE CONDUIT AND BLOCKS MAY BE INSERTED AND REMOVED FROMSAID CAVITY AS A CONDUIT-BLOCK ASSEMBLY WHEN THE MOLD SECTIONS ARESEPARATED.